Power device



March 8, 1932. A. BuLLocK 1,843,992

POWER DEVICE Piled Jly 14, 1930 3 Sheets-Sheet l H frog/v5 K Muth 3,1932- A. auLLocK POWER DEVICE Filed July 14, 1930 3 Sheets-Sheet 2 f4fo/QA/ex March 8, 1932. je.. BULLOCK 1,848,992

POWER DEVICE ril-ed Ju1'y14. 195o 3 sheets-sheet 3 HTTo/QNEY.

Patented Mar. 8, 1932 PATENT OFFICE ALBERT BUL-LOCK, OF LOS ANGELES,CALIFORNIA POWER DEVICE Applicatin. Yfiled July 14,

My invention relates to a device for transforming rotary motion, toreciprocating motion and relates particularly to a reciprocating devicewhich may be used for pumping oil wells. IMy invention departs from thecrank principle of reciprocating a member, such as a pump piston, bymeans ofV a rotating crank. In this oldmethod common to reciprocatingpumps, the pressure exerted against the piston by the crank and thespeed of the piston both vary in accordance-with the position of thecrank by which the piston is operated. My invention provides a meanswhereby the speed of the piston or reciprocating parts is maintainedconstant throughout the length of the stroke, and the pressurel appliedto the reciprocating parts is also kept substantially constantthroughout the stroke thereof.

It is an object of my invention to provide an elongated rack havinginwardly facing teeth, and a pinion gear adapted to engage the rack,this pinion gear being laterally movable and being provided with meansfor moving it from one side to the other of the elongated rack' duringreciprocation of the rack by means of the pinion.

A further object of the invention is to provide a reciprocating orpumping device of t-he above characterhaving means for holding thepinion in one or the other of its eX- tremes of lateral movement so thatthe pinion will' bemaintained in proper operating en.- gagement with theside teethv of the rack,

and it is a further object of the invention to provide an eccentricsupport for the pinion so constructed that the pressure ofthe pumpingaction. thereagainst will hold the pinion in a lateral position so as topositively engage 40 the side teeth of the rack.

A further object of the invention is to provide locking means,preferably of toggle form, for holding the pinion in engagement with theside teeth of the rack, and to provide an engagement means which willmove with the rack and engage the locking means in a manner to operatethe same.

A further object of the invention is to provide a reciprocating devicehaving a frame provided with a vertical guidey in which an 1930.V serialNo. 467,702.

elongated rack is slidablycarried, and a laterally movable gearmechanism adapted to engage the rack and to move back and forth fromside to side of the rack as the rack is reciprocated upwardly anddownwardly by the gear mechanism. In this preferred form. of theinvention I prefer to employ a gear mechanism consisting of a pinionwhich engages the rack, anda train of speed reduclng gears for turningthe pinion, this train of speed reducing gears being carried in alaterally movable structure which also supports a power device, such asa motor, for delivering power to the mechanism.

Further objects and advantages of the invention will be made evidentthroughout the following part of the specication.

Referring Vto the drawings, which are for illustrative purposes only,

Fig. l is a side elevation of a preferred form of my invention. Y

Fig. 2 is a horizontalcross section, drawn to reduced scale, on a planerepresented by the line 2 2 of Fig. 1.

Fig. 3 is an enlarged cross section on a plane represented by the line 33 of Fig. l, showing the gear mechanism of my invention.

Fig. 4 is a fragmentary section on a plane represented by the line i- 4;of Fig. 3, show-V ing the locking mechanism of the invention in lockedposition during downward movement of the rack member of the invention.

F ig. 5 is a fragmentary cross section similar to Fig. 4, showing thelocking mechanism in unlocked position during the upward movement of therack member.

Fig. 6 is an enlarged elevational view of the eccentricsupporting meansfor the pinion which drives the rack member of the invention.

Fig. 7 is an elevational view of a Vform of my invention employing a camfor positively moving the pinion into engagement with opposite sides ofthe rack member.

Fig. 8 is a cross section on Va plane represented by the line 8 8 ofFig. 7

Fig. 9 is an elevational view showing a form of my invention in whichthe pinion isv held in engagement with the rack by pressure of the rackagainst the pinion, which pressure is transmitted to an eccentricsupport by which the pinion is carried.

In the form of my invention shown in Figs. 1 to 6 I employ a framestructure 11 consisting of a square base 12 and four upright legs 13,which slope inwardly so as to define a rectangular pyramid. The upperends of the legs 13 are secured to a cap plate 14 from which guidemembers 15 and 16 extend downwardly, these guide members preferablyconsisting of structural channels with the webs thereof faced inwardly.The-lower ends of the members 15 and 16 are reinforced by means ofbraces 17 the ends of which are secured to the legs 13 by means ofbolts,as indicatedat 18. Asshown in Figs. 1 and3, supporting plates 20 aresecured on opposite sides of the guide members 15 and 16 by use of capscrews 21, these plates 20 being positioned just below the center oftherguides 15 and 16. Secured on the upper faces of these plates 20 arebearing blocks 22 consisting o f upper and lower cooperating halves 23and 24, the lower parts 24 being secured by means of bolts 25 to theplates 20, and the upper parts 23 being secured to the lower parts 24 bycap screws 26, as shown in Fig. 6. Within the bore 27 of each bearingblock 22 is an eccentric member 28 which consists of a cylindrical body.of external diameter to rotate in the bore 27 and having an eccentricopening 30 thereinl in which a bearing 31 is placed to 'receive a shaft32which extends through both bearing` blocks 22 and carries thereon apinion 33. This pinion 33 is disposed between the guides 15 and 16 andis adapted to engage a rack member 34 which slides vertically within theguides 15 and 16. The rack member 34 is in the form of an elongatedinternal gear and, as best shown in Fig. 1, has parallel substantiallystraight sides 35 and 36 on which side teeth 37 and 38 are respectivelyformed. The member 34 also includes upper and lower semi-circular ends40 and 41 which are provided with end teeth 42 and 43 faced inwardly andplaced so as to define semicircles, the side At-eeth 37 and 38 and theend teeth 42 and 43 constituting an elongated loop or elongated internalgear. VThe outer faces of the side portions 35 and 36 are provided withcast iron'plates 44 which make bearing engagement with the inner facesof the guides 15 and 16.

Ends 45 of the shaft 32 project through and beyond the eccentric members28 and have relatively large gears 46 of the same diameter securedthereon. These gears 46 are enclosed by the hollow leg portions 47 of agear casing 48, vthis gear casing 48 being preferably formed of upperand lower cooperating halves 50 and 51. rThe gear casing 48 includesat-the rightward ends of the side or leg portions 47 a hollow wallstructure 52 which supports an intermediate shaft 53 carrying smallpinions 54 at the ends thereof in engagement with the gears 46. On thecenter of the shaft 53 a large gear 55 is mounted, and this gear 55 isdriven by a pinion 56 carried on a shaft 57 having an end 58 projectingfrom the casing so that a pulley 60 may be mounted thereon, which, asshown in Fig. 1, is driven by a belt 61 extending from the pulley 62 ofa vmotor 63 mounted on the upper portion of the casing 48. The gea-rs46, 54, 55, and 56 constitute a reduction gear train for reducing downfrom the speed of the motor to the proper speed of rotation for thepinion 33; therefore, when the motor is turned on, the pinion 33 will bedriven at slow speed but with comparatively large torque. As shown inFigs. 3, 4, and 5, locking means 64 is provided for holding thesupporting means for the pinion 33 in such position that the pinion willengage a side of the rack member 34. By supporting means for the pinionis meant those parts for carrying the pinion 33 in position foroperation, and includes the shaft 32, the bearings 31, and theeccentrics 28. The locking means 64 consists of metal rings 65surrounding the shaft 32 inposition between the eccentrics 28 and theends of the pinion 33, and toggle links 66 which are hinged to the rings65 at 67 and to pins 68 carried by lugs 7 0 on the outer face of theguide member 15. In Fig. 4 a toggle link 66 is shown in operativeposition so as to hold the pinion 33 against the right side portion 37of the rack member 34 and in engagement with the teeth 38 thereof. Itwill be noted that the pin 67- is disposed below a hori- Zontal lineextended through the centers of the pin 68 and the gear 33 so that thethrust exerted against the gear 33 in leftward direction will not causethe toggle to collapse but will hold the stops 72 and 73 of the ring 65and the link 66 tightly together. In Fig. 4 the gear 33 is rotating inthe clockwise direction indicated by the arrow 74, and the rack member34 is moving downardly, the

upper end teeth 42 thereof approaching the upper portion of the pinion33. As the teeth of the pinion 33 come into engagement with the irstpart of the end teeth 42, an arm or dog 75 projecting rightwardly fromthe ring 65 is engaged by an actuating pin 76 mounted near the upper endof the rack member 34, thus rotating the ring 65 in clockwise directionso as to cause the toggle pin 67 to swing upwardly, whereupon the toggleformed between the ring 65 and the link 66 may collapse intosubstantially the positions shown in Fig. 5, in which the rack member 34is being carried upwardly or through a lifting stroke by the pinion 33.

The eccentric 28 is so designed that pressure exerted thereagainstduring proper operation of the device will hold the pinion 33 inengagement with one side or the other of the rack member 34. In Fig. 6the axis of the eccentric 28 is designated by the point 77,

and the axis of the opening '30 andthe shaft 32-extendingV therethroughis indicatedbythe .point 78. lVhen thefeccentric 28 .is partiallyi-'otatechthe axis 78 willitraversean arc 80 so as to move intothe-postion 81, whereupon tthe Vshaft32 will then assume the positionindi- `through which the pinion 33 mustmove laterally across the endteeth 42 ofthe rack member from engagement with -the side teeth -38 toengagement with the side teeth 37.

Villen the vpinion 33 is in the position in which it is shown in Fig. 4,both of the eccentrics 28 are in `the position shown in Fig. 6, theshaft 32 -being in such position that its axis coincides with the point78. As the pinion 33 engages and rolls leftwardly across the upperend-teeth 42, the axis of the shaft 32 is swung upwardly and'thendownwardly in leftward direction through the path indicated by the arcinto the ,position designated bythe point 81, the eccentrics 28 rotatingat this time so as to cause engagementfof the shoulder with the stop 83.

During the l-iftingstroke of the rack member 34, a reaction or thrustis'exerted downwardly by the teeth 37, and a lateral thrust in rightwarddirection :is produced bythe engagement of the sloping facesof thepinion and rack teeth, these teeth -being preferably formed with a 20engagement or thrust angle. The eccentric is so designed that thecomponent of the vertical and vlateral forces above mentioned will liealonga line such as .indicated by the arrow 86 which, when extendedthrough the point 81, will lieto the left of the cent-er 77 of theveccentric 28, thus producing a force tending to rotate the eccentric inanti-clockwise direction vand to hold .the Apinion 33 positively in.engagement with .the leftward teeth 37 of-the'rack 34. In view Aof thefact that the load on the eccentric is constant during the liftingstroke ofthe rack .member 34, the action of the eccentric is sufficientto hold the ypinion'33 in engagement with the leftward teeth 37 of therack, but it is evident that locking means of the same character asthe'locking means 64 may beem- .ployed-to lock the pinion 33 in leftwardposition as well as in rightward position. Duringthe upward stroke oftherack vmember '34, the load Amay be-indeterminate; therefore, the use ofthe locking' means 64 is advisable. In Fig. 5 FI show Va disengaging pin87 at the lower end of the rack member 34, which engages the lug 75 -ofthe toggle mechanism when the pinion 33 engages and rolls'rightwardlyacross the lower end -teeth 43, causing the ring'65 to rotate inleftward or anti-clockwise direction so as to swing thetogglearm66downwardly fromthe fposi'tionin which it is shown in Fig. vI5 intothe/position Vinfwhich it isshown in F ig. -4. In this manner I fhaveprovided thedevice with means for vpositively actuatingthe locking meansfor holding the pinion-A33 in yengagement withside teeth of therackmember or oval .gea-r.

As shown in Fig. 1,.apump shaft 901is-connected to vthe lower end `ofthe rack member 34 by means of a cushioned connector 91 which consistsof a lcylindrical 'frar'ne92, the

upper end of whichis hinged lat 93 .to the lower end'ofthe rack member 34, and the interior of which carries a body of resilient material 94,suchasrubber.k A plate or l.piston 95is-secured to the upper,endofztheshaft 90 :so as to rest on the-upper face ofthe resilient4body'94 and to absorb shocks which may be incurred at Vthe ends of thestrokeso'f the rack members' 34. vThrough a Vsimilar cushionedconnectorf96, the upper end of fthe rack member 34 is connected to acounterbalance cable 97 which extends overa pulley98 and 'has acounterweight 100 secured to the outerendthereof. l

The'frame v111 is supported on foundation blocks 101 by means of lrubbercushions :102 contained in cup-shaped .members 103 .into which plungermembers Y104 proje'ctfdownwardly from the corp-nersaofthebase structure12 of the frame 11.

'Ihe gear casing 481is `held in horizontalposition and prevented `fromrotating onthe shaft327b'y means ofva link 105 which-is secured to aclevis 106 mounted on the base structure 12of the frame 11 and .issecured to a bracket 107, which projects rightwardly from the casing 48,by means of a cross pin 108.

In Figs. 7 and 8 I showin simple manner a formfo'f my inventionin whicha pinion 110 is positively movedfrom side toside of an elongatedinternal vgear Ior rack member 111. In this form of lthe-invention therack member is carried in vertical sidebars 112 which project upwardlyfrom a base block 113. By means of horizontally vprojecting pins orshafts 114, vertical arms I115 are extended upwardly on each side lofthe rack member 111, these arms having bearings 116 and 117 at the upperends thereof. The pinxion 110 Iiscarried on Va shaft -118,.the forwardend 120,0f which is -supported infthe bearing lowers in the .form ofrollers 125 and 126are 4 finountedin iposition `to be engaged by :thecircular cam. 123 .as such cam is rotated, ywhereby to cause the shaftV-11'8 -to swing from ,one sideto the otherof :the rack-member 111 Vinaccordance with the reciprocation thereof. To rotate the cam 123 inproperly timed relationship to the rotation of the pinion 110 -securedto the shaft 118, this arrangement of gears accomplishing the desiredreduction of speed for turning the cam 123 slowly as compared to therotation of the pinion 110. The relative speeds of the cam 123 and thepinion 110 depend on the ratio existing between the pinion 110 and therack member 111. If a one-to-one ratio between the pinion 11() and therack 111 is established, the cam 123 will rotate at the same rate ofspeed as the shaft 118 and in such instances may be secured directlythereto. When the ratio of the pinion 110 to the rack 111 is increased,

fthe ratio of the rotation of the cam 123 to the pinion 110 is decreasedin proportion inverse to the ratio of the pinion to the rack member. Asa means for rotating the shaft 118 I have shown a pulley 132, andprojecting upwardly from the rack member 111 I show a rod 133 whichprojects into a counterbalance cylinder 134 mounted at the upper lendsof the side members 112, and carries a piston 135 thereon. As the piston135 moves downwardly, it compresses fluid, such as air,

within the lower part of the cylinder 134, thus building up acounterbalancing pressure against the under face of the piston 135,which pressure resists downward movement of the rack 111 and the partsto which such rack is attached.

In order thatthe cam 123 may be properly timed with the operation of thepinion 110 4and the rack 111, I have found that the teeth in therespective members 110 and 111 must be proportionedin accordance with afixed rule, and for the design of a reciprocating mechanism of thecharacter shown in Fig. 7, I have developed the following formula:

T1|=RN+ Te'- (Te-N) in which Y Tr=teeth in rack Te=teeth in end gearsN=number of teeth in pinion R=ratio of turns of pinion to reciprocationsof rack.

' In the use of this formula let it be assumed that the ratio of thepinionjtov the rack is four-to-one, so that the pinion '110 makes fourrevolutions for one complete reciprocation of the rack. In the pinionthere are sixteen teeth; therefore, the rack should have the equivalentof sixty-four teeth. The curved end portions 14() each have nine teethso as to form halves of an eighteen-toothed gear. Owing to the fact thatthe pinion 110 rotates through only a small part of a revolution duringthe time it is traversing the circular ends of the rack 111, eightyteeth must'be employed, whereas from a cursory lside of the rack 157.

consideration of the problem it would appear that the number of teeth inthe rack would be four times the number of teeth in the pinion, lorsixty-four. Using the samie formula, thirty-two teeth would be requiredin the rack of a device of the above character having a one-toone ratioand a pinion of sixteen teeth and end gears of nine teeth each. In theform of my invention shown in Fig. 9, I show a pinion 150 supported by alaterally extending shaft 151 which projects into the eccentric opening152 of an eccentric member 153 carried in a bearing member 154 which issecured to guide members 155 by means of bolts 156. A rack member 157 issupported in the guide members 155 and is connected to a continuous loadby means of a shafto-r rod 158 which projects downwardly from the lowerend thereof. In this device the pressure exerted against the rack isalways in downward direction, with the result that no matter which waythe eccentric 153 may be turned the result of the downward pressure andthe pressure exerted by the teeth-will always produce a rotation of thepinion 150 into engagement with a cooperating side of the rack 157. Asshown in Fig. 9, the eccentric 153 is rotated rightwardly so thatdownward pressure thereagainst tends to hold the shaft 151 and thepinion 150 in rightward direction. The rotation of the pinionv150, beingin rightward direction, as indicated by the arrow 160, causes the teeththereof to traverse the upper end of the rack in leftward direction soas to swing the center point 161 of the shaft 151 and the pinion 150over to the position indicated by the point 163, at which time the teethof the pinion 150 will be in engagement with the leftward side of therack 157 and will move the rack upwardly, the pressure of the rack andof the interengaging teeth then causing the pinion 150 to remain inleftward position until the rack is raised to its full extent to bringthe teeth at the vlower end of the rack into engagement with the pinion150, at which time the pinion 150 will move rightwardly into a positionfor engagement with the rightward In this form of the invention I haveillustrated how my invention may be practiced without external orauxiliary means for moving the pinion from side to side of thereciprocating rack, employing only the normal pressure encountered inthe operation of the device for accomplishing this movement andmaintaining the pinion in engagement with the sides of the rack member.v i

Although my invention has been initially designed for use as a pumpingjack for pumping of oil wells, it is recognized that the reciprocatingand rotary parts thereof may be employed in many other mechanisms.Although I have herein shown and described simple and operativeembodiments of my invention, it is recognized that certain parts orelements thereof are representative of other parts, elements, ormechanisms which may be employed in substantially the same manner toaccomplish substantially the same results; therefore, it is to beunderstood that my invention is not to be limited to the detailsdisclosed herein but shall be accorded the scope of the following claim.

I claim as my invention:

A power device of the character described, including: a reciprocatingrack member having teeth arranged to define an elongated loop includingside teeth defining substantially straight lines and end teethsubstantially defining semi-circles connecting across the ends of saidsubstantially straight lines; slide means supporting said rack member apinion engaging the teeth of said rack member; a pinion support forsupporting said pinion inoperative position, said pinion support beingmovable in a direction lateral with respect to the line of movement ofsaid rack member so as to permit movement of said pinion by said endteeth from one side to the other of said rack; and means operative inresponse to pressure of said rack member against said pinion for holdingsaid pinion support in its eXtreme positions so as to hold said pinionin engagement with said side teeth of'said rack member after movement osaid pinion by said end teeth.

In testimony whereof, I have hereunto set my hand at Los Angeles,California, this 9th day of July, 1930. l

ALBERT BULLOCK.

